The long-term objective of this research is to understand constraints on balance control in the child with cerebral palsy during both static and dynamic tasks. Aims of the project are to determine the limitation of balance abilities in children with cerebral palsy when balance is disturbed with varying magnitudes, to determine the contributions of muscular and non-muscular forces to balance control, and to determine the contributions of training to the emergence of efficient balance strategies. Electromyography, kinematic, and kinetic recordings will be obtained during stance perturbations. The data will serve as a basis for designing intervention strategies that are appropriate to the children's specific balance constraints.